SQL Server Authentication and user logon, SQL Server
During installation, the SQL Server database engine is set to "Windows Authentication Mode" or "SQL Server and Windows Authentication mode ". After installation, you can change the Authentication Mode at any time.
If "Windows Authentication Mode" is selected during installation, the sa logon name is disabled and the installer assigns a password. If you change the Authentication Mode to "SQL Server and Windows Authentication Mode" later, the sa Login Name is still disabled. To use the sa LOGIN Name, use the alter login statement to enable the sa LOGIN Name and assign a new password. The sa Login name can only be connected to the Server using SQL Server Authentication.
Refer to: https://msdn.microsoft.com/zh-cn/library/ms188670.aspxchange server ID verification.
Change Security Authentication Mode
Enable sa Login Name
Enable sa Login Name
Failed to solve connection/Add User
When we open Microsoft SQL Management Studio and try to connect to the server, if the following error occurs:
Cantreaty connect **
Login failed for user '***'. (Microsoft SQL Server, Error: 18456)
The user may not be enabled, the user name/password is incorrect, the user authentication method is incorrect, or the user does not have management permissions. Try the following link.
Http://itproguru.com/expert/2014/09/how-to-fix-login-failed-for-user-microsoft-sql-server-error-18456-step-by-step-add-sql-administrator-to-sql-management-studio/
1) log on through the default settings during installation and use Microsoft SQL Management Studio
2) Select "Security"-> "Logins" in Object Explorer, find the username, and click Property. If no user is required, select "New Login" and enter the user name or Search to find the user.
3) Select Windows authentication or SQL Server authentication as the user authentication method (enter the password)
4) if you want to grant the user the permission to access Management Studio, you need to check sysadmin in "Server Roles ".
5) for SQL Server authentication, Login needs to be Enabled in Status